Figure 16. Number of data entries in simulation program
In blockchain, each block generation process consumes a certain amount of hash computing power, therefore it can be regarded as every block has its own hash computing power inherently. Furthermore, since new blocks are generated based on former blocks, the hash computing power in one block would be accumulated. Any attacker trying to tamper with the data in one block should owns higher hash computing power than the one possessed by that block. Fig. 17 shows the hash computing power of block 1-7. From the diagram, it can be seen a former block always has higher hash computing power than that of newer ones. And as time goes by, the hash computing power of all blocks would increase. Such phenomenon can be treated as an evidence for proving the safety of blockchain with proposed P-PoW algorithm: the longer time the system runs, the harder an attack could be made.